US2594390A - Device for viewing slides - Google Patents

Description

Patented Apr. 29, 1952 UNITED STATES PATENT OFFICE 3 Claims.

My invention relates to apparatus for viewing pictures orjslides which are exchangeably inserted in the apparatus.

Objects or my invention are to secure a lightdiiiusing sheet, a slide-support and a lens for observation of the slide in proper mutual positions by simple and reliable means, and to provide the apparatus with a structure that can be easily, accurately, inexpensively and quickly made and assembled, and that will not be weakened by heat from a light source positioned in the apparatus.

Other objects are to adapt the apparatus to slides of various sizes, to perform this adaptation easily andquickly and by means incorporated in and permanently connected to the apparatus,

thereby to'make unnecessary the insertion of the slides in frames of which each fits a particular size of s1lde,"and'to avoid the inconveniences and expenses which result from the use of such frames and from the possibility of mislaying the same.

Still other objects and advantages will appear from the following description of an exemplifying embodiment of my invention, from the appended claims and'from the accompanying drawing in which:

Fig. 1 shows a cross-section of an illustrative embodiment of my invention, taken along the line Il in Fig. 2, an electric bulb and its socket being represented non-sectionally.

Fig. 2 shows a cross-section taken along the line 2-2 in Fig. 1.

Fig. 3 showsa partially sectional view of the same embodiment, the sectionally represented parts being out along the line 33 in Fig. 1.

Fig. 4- shows a cross-section of a broken off part of the same embodiment, this cross-section being taken along the line 4-4 in Fig. 1.

Fig. 5 shows a side view of a lens-holding plate which is an element of the embodiment shown in Fig. 1.

Referring to the drawing, numeral 5 indicates a housing which may be made of sheet metal walls united in any suitable manner after the inner parts of the embodiment have been affixed to the walls. These walls comprise two parallel vertical walls 6 positioned laterally with respect to the viewer and a wall 1 facing the eyes of the viewer and being preferably positioned on; top

. of the housing in an obliquely declining direction.

The wall I has an outwardly projecting portion 8 pressedout of this wall in such a manner that this portion forms a circular shallow recess of the inner space of the housing. The wall portion 8 has an opening 9. A magnifying glass or lens II is inserted in this recess and extends across the opening 9. A number of lobes or flat-projections l'2 extend from the inner side of the wall I at the circumference of its recess and are bent over the rim of the lens I 1 whereby the latter is afllxed to the housing without impairing the outer appearance. The lobes 12 may be ailixed to the wall 1 in any suitable manner. For example, these lobes may be. stamped out, integral parts of a ring l3 of sheet metal which is welded or. soldered to the wall I. The lobes I2, when stamped, may be positioned about vertically to the ring l3 as shown in Fig. 5 in dotted lines. After insertion of the lens into the recess of the wall 1, the lobes are bent as shown in full lines in Figs. 1 and 5.

A plate l4 extends across the housing from one wall 6 to the other and is inclined parallel to the wall '1 or its opening 9. A rim or strip [6 forms an angularly and upwardly bent continuation of the plate M. The opposite rim ll of this plate may be similarly bent. The plate I4 serves to support a slide at a suitable distance from the lens I I. The rim contributes to this support and serves as a guide for positioning the slide. The plate 14 has a centrally located aperture I 5 which has such a distance from the rim l5 that the pictorial transparent area of the slide overlies this aperture when the'lower edge of the slide contacts the rim IS. The plate I4 is affixed to the housing 5 in any suitable manner.

Slides of various sizes can be placed on the plate [4 if each of these sizes is sufficiently large to reach from the rim it over the entire aperture l5. In order to place smaller slides in positions centred with respect to the line of vision and without side light from the aperture l5 disturbing the observation, a second plate 3 is provided which has a smaller aperture is. The plate I8 is hinged to the plate M by a shaft 2i extending laterally from the apertures l5 and I9 and perpendicularly to the walls 6. This shaft passes through eyelets 22 formed by a rim of the plate l8 and through similar eyelets 23 forming extensions of the plate I4 whereby the plate I8 is turnable about the shaft 2| to and fro between a position parallel to and overlying the plate II and a position adjacent to the rim l1 and substantially perpendicular to the plate l4. Reaching the latter position, the plate l8 snaps over a small inner projection 24 of one of the walls 6 or of similar projections of both walls 6. The projection 24 is formed by impressing the wall 6 from the outside and engages the plate I8 releasably whereby this plate is prevented from falling back unintentionally.

When the plates l4 and I8 are in parallel positions, their apertures l5 and I9 are concentric. The plate It is provided with an angularly'bent rim 25 similar to, but smaller than the rim IS. The distance of the rim 25 from the center of the apertures is smaller than the corresponding distance of the rim 16 whereby the rim 25 forms a suitable guide and support for smaller slides having pictorial areas positioned over the aperture l9.

A light-diffusing sheet 26 is positioned under and across the aperture is and is attached to the plate M in such a, manner that no separate parts are required, that the sheet 23 can be easily brought into the proper position, and that solder or other connecting means are avoided which may weaken under the heat of a light source or electric bulb 21 positioned closely under the sheet 26. For this purpose, ledges or strips 28 are stamped out of the plate I and are bent so that their cross-sections form right angles. The sheet 26 has a rectangular shape larger than the aperture l5, whereby the edges of the sheet extend beyond this aperture in contact with the plate I4. The strips 28 extend along two parallel edges or along three edges of the sheet andr'each around the respective sheet edges, forming together with the plate 14 channelsfor engagementof these edges; Also stamped out of the plate Mare one or more projections 29 which abut the fourth edge of the sheet.

" The sheet 25 is preferably made of resilient material, for example, of plastics and can be brought into the described position by shifting the sheet slidingiy over the projections 29 into the channels formed by the strips 28. First the sheet slides in the two parallel channels, then it enters the third channel and snaps over the projections 29 whereby the sheet is secured in the space between the strips 28 and the plate I4.

The bulb 2? is positioned at that side of the sheet 25 which is opposite to the lens H and may be afiixed to the housing 5 in any suitable manner, for example, by a socket 3!. The bulb may be supplied with current and may be provided with a switch in well known manner.

Each or one of the walls 8 is provided with a window 32 for the insertion of slides. window may form a rectangle of which three sides are flush with the facing surfaces of the rims IE and i: and with the upper surface of the plate is. An extension 33 of the plate I8 projects through a window 32 and forms a handle for changing the position of this plate.

The magnifying lens H is so designed that the picture viewed through the lens appears in undistorted flatness whether this picture has about the same diagonal width as the lens or has a considerably smaller width. I have found that the lens types hitherto used in picture-viewing apparatus cannot attain this result, and I have solved this problem by using a bi-convex lens H of equal diopters at both sides, these diopters being measured to correspond to a focal length which is equal to twice the diagonal width of the largest picture to be viewed or to the diagonal width of the aperture 15. This lens cooperates with the movably connected slide-supporting plates is and is in adapting the described apparatus for viewing transparencies or pictures "of considerably different sizes.

I desire it understood that my invention is not confined to the particular embodiment shown and described, the same being merely illustrative, and that my invention may be carried out in other ways within the scope of the appended claims without departing from the spirit of my invention, as it is obvious that the particular embodiment shown and described is only one of the many that may be employed to attain the objects of my invention.

Having described the nature of my invention, what I claim and desire to protect by Letters Patent is: Y i

1. An apparatus for viewing pictures, comprising a housing having an opening,'a lens aifixed to said housing and extending across said opening, a slide-supporting plate afiixed to and ex- This tending in said housing parallel to said opening, having an angularly bent rim for guiding a slide and having an aperture, a light difiusing sheet attached to said plate and extending across said aperture, a second slide-supporting plate having an aperture smaller than said first mentioned aperture, being hinged to said first mentioned plate along an axis lateral from said apertures and being swingable from a position parallel to said first plate into a position substantially perpendicular thereto, said two apertures being concentric when said swingable plate is in said parallel position, said swingable plate having an angularly bent rim for guiding a slide which is parallel to said first mentioned rim'and has a smaller distance from the center of saidapertures than the first mentioned rim, and a light source positioned at that side of said sheet which is opposite to said lens.

An apparatus for viewing pictures, comprising a housing having an opening, a lens anixed to said housing and extending across said opening, a slide-supporting plate affixedto and extending in said housing parallel to said opening and having an aperture, a light-diffusing sheet attached to said plate and extending across said aperture, a second slide-supporting plate having an aperture smaller than said first mentioned aperture, being hinged to said first mentioned plate along an axis lateral from said apertures and being swingable from a position parallel to said first plate into a position substantially perpendicular thereto, and a light source positioned at. that side of said sheet which is opposite to said lens, said housing having a side wall perpendicular to said axis, said wall having an impression forming an inner projection engaging said swingable plate in said perpendicular position of the same.

3; An apparatus for viewing pictures, comprising a housing having an opening, a lensafiixed to said housing and extending across said opening, a slide-supporting plate aifixed to and extending in said housing parallel to said opening and having an aperture, a light-diffusing sheet attached to said plate and extending across said aperture, a second slide-supporting plate having an aperture smaller than said first mentioned aperture, beinghinged to said first mentioned plate along an axis lateral from said apertures and being swingable from a position parallel to said first plate into a position substantially perpendicular thereto, and a light source positioned at that side of said sheet which is opposite to said lens, said housing having a side wall perpendicular to said axis,said wall having a window for the insertio'nof a slide, said swingable plate having a handle. projecting through said window.

SYDNEY BRUMBERGER.

REFERENCES CITED The" following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,450,555 Lepine Apr. 3, 1923 1,487,173 Manion Mar. 18, 1924 1,593,302 Cocanari July'29, 1929 2,010,551 McConalogue' Aug. 6, 1935 2,059,197 Backer et' a1. Nov. 3, 1936 2,129,759 Goldman Sept. 13, 1938 2,445,929 Sturgess July 27, 1948 2,446,052 Loessel et a1. July 27, 1948

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